DOCS. 315, 316 MARCH 1917 307 or here somewhere in the countryside? There are several places in our eastern provinces as well as on the seashore where one could stay comfortably for a few weeks; and you could make your selection such that you are not entirely shut off from scientific interaction but do not have to join the daily discussions. If we can be of any assistance in this regard, I ask you please to tell me. But perhaps the Swiss air is better for you after all, and naturally you will be attracted by the prospect of having your children nearby.[3] In the meantime, ... I have set up a “Lagrangian function,” dependent only on the present-day distances r and velocities v, for an arbitrary number of celestial bodies. Precisely in the second-order terms (in which form they must be considered in the explanation of Mercury’s perihelion motion) this function assumes the following formal:[4] L = ^ E(*) ! 4 + Ri + 77 £(X?K3 iyt + v]) - 7(vi • "i) + + IV C I .0¿iO¿ 3 í OLiQt\ aiO-\ 1 OiiOi2! + a,a2 , i__ 5 V Rj Ri ) ri rij 2r?- 7TC , /1 1 1 ----1"--1“ - « VijTji rjira TuTij After the conversations you had with our Berlin colleagues last fall, I received very friendly letters from Planck and Waldeyer.[5] I have not yet found occasion to take up the matter again. I do not want to be presumptuous, considering that the issue involved is primarily of importance to Germans: Nevertheless, the attitude of the gentlemen mentioned gives me full confidence that, after the war, something will happen in the direction I wish. With cordial greetings from both of us as well as from de Haas and my daugh- ter, and with best wishes, devotedly yours, H. A. Lorentz. 316. From Friedrich Adler Vienna, 1 Alser St., 23 March 1917 Dear friend Einstein, Your letter was a welcome joy, above all, because it proved to me what I had hoped and suspected, that our earlier personal relations have remained the